A misfiring Pakistan warmed up for the World Twenty20 semi-finals with a four-wicket victory over Bangladesh.

They bowled the Tigers out for 140 despite never really hitting top gear, as only debutant Zunaid Siddique resisted with 71 off 49 deliveries.

After Imran Nazir retired hurt in the first over, Shahid Afridi blasted 39 before the spinners slowed the scoring.

From 59-0 Pakistan slumped to 119-6 and though Nazir returned to see them home, they will need to improve in the semis.

They slipped into their old complacent habits to give Siddique three lifelines - Misbah-ul-Haq fluffed an easy opportunity at mid-wicket when he was on two, while Nazir and Umar Gul failed to grasp more difficult catches at deep square-leg and long-on when he was on 26 and 44.

After that the 19-year-old left-hander produced some delightful straight and cover drives, and took a real liking for thrashing the ball over the mid-wicket region as he reached his fifty off 35 balls.

But there was little support for him as Aftab Ahmed was stumped off Mohammad Hafeez, captain Mohammad Ashraful was lbw to a quicker one from Afridi and Saqibul Hasan got a leading edge back to Hafeez.

Siddique responded by dispatching Hafeez over mid-wicket for successive sixes but his eventful knock was ended when another big hit off skipper Shoaib Malik was snapped up by Misbah at deep mid-wicket.

Malik also had Nadif Chowdhury caught behind and Mohammad Mahmudullah was run out after Mashrafe Mortaza's drive deflected off him and into the hands of Gul.

Mohammad Asif, who had been lacklustre earlier, returned to bowl Mortaza with another lifeless delivery and burst out into laughter after ending Abdur Razzak's bid for a reckless single by hitting the target.

There more smiles all round when Gul cleaned up Syed Rasel in the final over - it was one of those days.

Nazir did not share in the mirth around the ground when a delivery from Mortaza hit him in the nether regions and he was forced out of the action in the first over of the reply.

The way Afridi set about the bowling, there was the risk of more injury as he blasted the seamers and spinners away with regularity, while Hafeez also took a liking to Rasel as 50 came up inside five overs.

But Hafeez mis-timed Rasel to long-off, Afridi chopped Abdur Razzak behind after belting Rasel over the long-on rope, and left-arm spinner Razzak had Younus Khan stumped off a wide.

The runs dried up as Malik was snapped up at deep square-leg and Misbah was lbw second ball after missing a straight one from Mortaza.

When a casual Salman Butt was run out by Mushfiqur Rahim to make it 119-6, Bangladesh were still in the game.

However, Nazir came back to thrash Mahmadullah over square-leg for six and crash two more boundaries off Mortaza to help seal a far from convincing victory.

Bangladesh captain Mohammad Ashraful:"Again we were 10-15 runs short but our boys have done a very good job in this tournament.

"We beat the West Indies and played some decent cricket but here and against Sri Lanka we were 20 runs short, we bowled well but didn't bat well.

"Still, I think it's been a very good tournament.

Pakistan captain Shoaib Malik:"We must give credit to their spinners, they bowled superbly, on the right spots and that's why they took a few wickets.

"In Twenty20 you don't have much time to take decisions - if you have plans you have to stick to them.

"I asked Afridi where he wanted to bat - I don't want to put pressure on any player.